Hydrodynamic coupling



Dec. 8, 1970 TETSUYA llJlMA I HYDRODYNAMIC COUPLING Filed Dec. 5, 1968 3 Sheets-Sheet 1 Dec. 8, 1970 TETSUYA IIJIMA HYDRODYNAMIC COUPLING 3'Sheets-Sheet 2 Filed Dec. 5, 1968 Dec. 8, 1970 TETSUYA IIJIMA -.HYDRODYNAMIC COUPLING 5 Sheets-$heet 5 Filed D86. 5, '1968 Fig. 4

United States Patent HYDRODYNAMIC COUPLING Tetsuya Iijima, Tokyo, Japan, assignor to Nissan Jidosha Kabushiki Kaisha, Yokohama, Japan Filed Dec. 5, 1968, Ser. No. 781,321 Claims priority, application Japan, Dec. 20, 1967, 42/ 81,429 Int. Cl. F04d 29/18 US. Cl. 416-197 1 Claim ABSTRACT OF THE DISCLOSURE A fabricated hydrodynamic coupling device each vane being connected by tabs to slots of an impeller outer shell and a core element and is assembled without flexing the vanes, without other retainer means nor retaining devices, only by folding tabs to the core element.

The present invention relates to hydrodynamic coupling devices and more particularly to a fabricated vaned element of such a device.

Fabricated hydrodynamic coupling devices have been proposed wherein the vaned impeller and turbine elements each comprises a substantially semitoroidal shell, a plurality of semicircular vanes received within the shell and having tabs received Within slots in the shell and a semitoroidal core having slots receiving tabs on the opposite side of the vanes, these component parts of the vaned element being formed of sheet metal stampings.

One such known device comprises an annular retainer plate connected to the inner periphery of the shell and engaging the radially inner ends of the vanes to maintain the tabs in the vanes within the slots in the shell. However, use of a retainer plate is limited to vanes having suflicient length to enable their radially inner ends to engage the annular retainer plate. Also, an additional fabricating process is necessary to attach the retainer plate to the vanes.

Another known device comprises a specially formed slot of the shell element as a radially innermost slot to receive a corresponding tab of the vane. However, the vanes must be flexed to assemble the vane, and a very accurate forming process is necessary to both vane forming and slot forming. To avoid the inaccuracy, another device punches the portion of the shell adjacent the tab after assembly to deform the material of the shell and to secure the tab of the vane to the shell. However, the punching process is complex and the use of such a process makes it difficult to attain the desired uniform retaining result.

It is an object of the present invention to provide a fabricated hydrodynamic coupling device formed of sheet metal stampings, having a simpler construction made by a simple assembly process, and more economically produced than known devices.

Another object of the present invention is to provide an improved coupling wheel element in which the securing or positioning of the element between the plates and the shell is accomplished only by tabs and slots, and only after the blades are assembled to the shell and the core and the tabs are rolled down are the wheel element components connected firmly without mechanical freedom.

A further object of the present invention is to provide the above mentioned wheel element which can be assembled without deformation of the blades, thereby eliminating any adverse effect on the hydrodynamic characteristics of the wheel element.

A still further object of the present invention is to provide the above mentioned wheel element having a minimum number of parts, simple construction, light weight and low manufacturing cost.

3,545,883 Patented Dec. 8, 1970 For the purpose of describing more particularly a preferred embodiment of my invention, reference will be made to the accompanying drawing, in which:

FIG. 1 shows a longitudinal sectional view of a portion of a hydraulic torque converter according to the invention,

FIG. 2 shows a longitudinal sectional view of a pump wheel shown in FIG. 1,

FIG. 3 shows a partial end view of the pump wheel shown in FIG. 2,

FIG. 4 shows a sectional view of the pump outer shell of the pump wheel shown in FIG. 3 along line 4-4 of FIG. 5,

FIG. 5 shows a partial end view of the pump outer shell shown in FIG. 4, and

FIG. 6 shows enlarged partial sectional view along line 66 of FIG. 2.

Referring to the drawings, more especially to FIG. 1, 1 designates a torque converter assembly. The torque converter assembly 1 shown in FIG. 1 is a three element assembly consisting of a pump 2, a turbine 3 and a stator 4. However, the present invention can be applied to any hydrodynamic coupling devices and the drawing shows only one preferred embodiment. The torque converter assembly 1 is utilized to transmit and convert torque by momentum change of fluid therein by means of the pump, the turbine and the stator. The main portion of the torque converter assembly 1 is. included in a vessel formed by a pump outer shell 5 and a cover 6 which secures a pilot boss 7 supported by a pilot bearing 8 which is secured to a crankshaft 9 of the engine. The other end of the torque converter provides a sleeve shaft 10 which is secured to the outer shell 5 and is supported by a bearing 11 which is secured to a casing 12.

The pump 2 comprises an outer shell 5, an inner core 13 and blades 14 to form spaces between the shell 5 and the core 13 forming a portion of a power fluid circulation path and the blades 14 are inserted substantially radially to define the spaces. The outer shell 5, the core 13 and the blades 14 are all fabricated from suitable metal sheet and assembled as to be explained in more detail hereinafter.

The turbine 3 also comprises: an outer shell 15 and an inner core 16 forming fluid circulation path, and blades 17 which are inserted substantially radially between the shell 15 and the core 16. The outer shell 15 is secured to a turbine hub 18 which in turn is spline connected to an output shaft 19.

The stator 4 comprises a ring 20 and a hub 21 defining a fluid path, and a plurality of radially disposed blades 22 to form an axial flow wheel. The stator 4 is supported through a one-Way brake 23 on a fixed shaft 24 which is secured to the casing 12. The one-way brake 23 is disposed between an outer race 25 which is secured to the hub 21 and an inner race 26 which is spline connected to the shaft 24 to allow rotation of the stator 4 only in the direction of rotation of the engine.

To the outer surface of the cover 6, a plurality of bosses 27 are secured, such as by welding to receive bolts 28 securing a drive plate 29 which is secured to the engine crankshaft 9 by means of bolts 30. The engine torque is transmitted through the crankshaft 9, the drive plate 29, bosses 27, and cover -6, to the pump outer shell 5. A portion of the torque is transmitted through the sleeve shaft 10 to an oil pump 31 to supply torque converter fluid, and a major portion of the torque is transmitted through the pump 2, the hydraulic fluid and the turbine 3 to the output shaft 19. The stator 4 furnishes the reaction torque through the casing 12 to change the flow direction of the fluid and increase the momentum of the fluid, thereby causing a multiplication of the turbine output torque in a manner well known in the art.

The pump 2 is shown in detail in FIGS. 2 and 3. The pump outer shell 5 is made from sheet metal to provide semitoroidal depression and radially spaced sets of circumferentially spaced slots 32, 33 and 34 as shown in FIGS. 4 and 5. Each blade 14 is also made from sheet metal and has a semicircular outer edge to fit within the semitoroidal surface of the outer shell 5. Each of the blades 14 is provided with three tabs 35, 36 and 37 extending radially outward of the semicircular margin of the blade, and fitting into the corresponding slots 32, 33 and 34 respectively. The alignment of the slots follows the line of contact between the outer shell 5 and the blade 14 so that no deformation of the blade is necessary to assemble the blades to the shell. The inner edge portion of the blade 14 is formed with a semicircular recess to receive the inner core 13 and is provided with two tabs 38 and 39.

The inner core 13 is also made from sheet metal to form a semitoroidal outer surface to engage the inner edge of the blades 14 and is provided with two rows of slots 40 and 41 to receive the tabs 38 and 39. The tabs 38 and 39 are inserted into the slots 40 and 41 and folded or rolled down fiat against the inner curved surface of the core 13 to lock the inner core 13 to the blades 14 and also to lock the whole pump assembly 2 as will be described in more detail hereinafter.

To assemble the pump wheel 2, the blades 14 are assembled to the outer shell 5 by inserting the tabs 35, 36 and 37 into the slots 32, 33 and 34 sequentially from the radially outer slot 32. As described, the slots are aligned substantially to the assembled line so that the assembly is easily performed and no deflection of the blades is necessary. The inserted blade 14 can be easily removed by rotating the blade about the radially outer slot 32. However, when the blade is pulled parallel to the axis of the pump 2, the blade 14 is retained by engagement of the edge surface 32a of the slot 32 and the edge surface 35a of the tab 35, as the surfaces 32a and 35a are substantially perpendicular to the axis of rotation at assembled position. After all the blades 14 are assembled in the outer shell 5, the inner core 13 is assembled by inserting the tabs 38 and 39 of the blade 14 into the slots in core 13. By folding or rolling down the tabs 38 and 39 flat against the surface of the core 13, the blades 14 can never rotate about the slot 32, thereby completing the assembly of the pump 2.

One of the important features of the present invention is that the blades are not connected to the shell without mechanical freedom, and only after the blades are assembled to the shell and the core is assembled and further the tabs are rolled down, are the pump wheel components connected firmly without mechanical freedom.

To assure firm connection of the pump components, when the core and the shell are in the assembled position without blades, the distance L between the radially outer corner 32b of the slot 32 of the shell 5 and radially inner corner 41b of the slot 41 of the core 13 is slightly shorter than the corresponding distance of the blades, i.e., between corner 35b of the tab 35 and radially inner corner 39b of the tab 39, according to the present invention. Thus, when the shell, blades and core are assembled the core and the blades are deformed slightly so that there is a firm connection by elastic engagement at portions 32a and 41b. The deformation is absorbed mainly by the core 13 so that no hydrodynamic eifect is produced as fluid channels are not deformed.

It will be appreciated that the vaned elements of a torque converter or fluid coupling according to the invention are formed of minimum numbers of sheet metal stamping, can be assembled by a simple process, and are light weight and economical compared to known fabricated vaned elements. Further, assembly is easier as deformation of the blade is not necessary, and fluid flow channels are maintained with accurate dimensions.

I claim:

1. In a vaned element of a hydrodynamic coupling including a hollow sheet metal shell having a generally semitoroidal surface provided with at least three series of slots each at circumferentially spaced locations on the interior surface of said shell including a first series of slots on radially outermost locations, the slots of each series being arranged in spaced circumferential relationship about the axis of said shell, a hollow semitoroidal sheet metal core being provided with at least two series of slots each at circumferentially spaced locations piercing through said core, and a plurality of sheet metal blades with an outer arcuate margin and an inner arcuate margin that corresponds in shape to the toroidal shape of said interior surface of the shell and outer surface of the core, respectively, and tabs corresponding to said slots of the shell and the core, improvements comprising said slots of the shell corresponding to each said blade being arranged to substantially align the longitudinal edges of the slots to predetermined fluid flow lines formed by the assembled blade to enable inserting the tabs of the blade without flexing the blade, the radially outermost marginal surface of each slot of said first series of slots being substantially perpendicular to rotation axis of said shell, the edge surface of said tab engaging said surface of said slot being also substantially perpendicular to said rotation axis, the distance between the radially outermost corner of said first series of the slots of the shell radially innermost corner of the radially innermost slots of the core at corresponding assembled positions being slightly shorter than the distance between the radially outermost corner of the radially outermost tab engageable to the shell and radially innermost corner of the radially innermost tab engageable to the core so that when the shell, blades and core are assembled the blades and core are elastically deformed slightly to effect firm clamping of the blades between said corner, clamping or positioning elements between the shell and the blades being said slots and tabs, and the shell, blades and core being assembled in mechanically clamped relationship only after the tabs are bent against the inner surface of the core.

References Cited UNITED STATES PATENTS 2,357,295 9/1944 Thompson 1031l5T 2,692,561 10/1954 Zeidler 103-115T 2,692,562 10/1954 Zeidler 1031l5T 2,701,531 2/1955 English 103115T 2,779,292 1/ 1957 Zeidler 103115T 3,316,622 5/1967 Jandasek 6O54X FOREIGN PATENTS 684,385 12/1952 Great Britain 60-54 EDGAR W. GEOGHEGAN, Primary Examiner US. 01. X.R. 

